Other actin-associated proteins and cell–cell adhesion proteins such as periaxin, Abi2, E/N-cadherin, β-catenins, and Arvcf (Armadillo repeat gene deleted in velocardiofacial syndrome) have also been implicated in secondary fiber cell organization,80–85 but the etiology of meridional row and secondary fiber cell disorder in these knockout mice has either not been studied or cannot be investigated due to the severity of the lens defects. The gene discussed is ABI2; the disease is 22q11.2 deletion syndrome.